What type of speakers? If they use optical or 3.5mm you can use an HDMI Audio Extractor. Like this one for example: here
I would also like to add to this and say that you can use the Bluetooth feature or 3.5mm headphone out for audio from the MacBook.
If you’re looking for an HDMI audio extractor, my go to brand is usually OREI since they’re good on price and pretty reputable.
On the MacBook make to change the audio output to headphones or speakers if you’re going to be using that for sound
An HDMI audio extractor would work very well in your set up.
I would recommend looking at this one since it’s built better : here
For sound if you wanted to use Bluetooth, you need an HDMI audio extractor if you go with the Epson 8350.
For the other two you can use a Bluetooth Transmitter that support APT-X. This is important because other Bluetooth devices can introduce an audio delay. You would plug the Roku stick into the projector and run a 3.5mm audio cable from the projector to the a Bluetooth Transmitter and then pair your speakers.
Monoprice Premium Bluetooth 5 Transmitter & Receiver with aptx HD
For the 8350 in order to get SDIF Optical or 3.5mm audio out you need to use a HDMI audio extractor, this is one that I always recommend due to high build quality.
OREI hda-912 4K 60hz 18g HDMI 2.0 Audio Converter Extractor spdif + 3.5mm output
